A suspect has been arrested in the May 24 shooting at the Brussels Jewish Museum in which three people were killed and a fourth was was critically wounded. Reuters reports that 29-year-old Mehdi Nemmouche was arrested in France “on suspicion of murder, attempted murder and possession of weapons, all in the context of terrorist activity” after being flagged by authorities during a routine customs search at a bus station.

Mehdi Nemmouche was detained on Friday after a random check at a bus terminal in the French city of Marseille showed he was carrying a Kalashnikov rifle, another gun and ammunition similar to those used in the shooting last weekend, French and Belgian prosecutors said.

Paris prosecutor Francois Molins told reporters Nemmouche had been carrying a video where a voice resembling his own claims responsibility for the shootings.

Belgium is reportedly seeking Nemmouche’s extradition from France, where he is a citizen.

According to Haaretz, Nemmouche is a resident of the French city of Roubaix, and was returning to France on a bus from Amsterdam via Brussels. He had reportedly served five jail terms in France and spend the bulk of 2013 in Syria, where he is believed to have fought with Islamist militant rebels in the Syrian civil war.

Among Nemmouche’s seized possessions was a video tape in which a voice resembling his own takes credit for the attack that killed an Israeli couple visiting Belgium and a French volunteer at the museum, and critically wounded a 23-year-old museum employee.

The voice in the video, thought to be that of arrested suspect Mehdi Nemmouche, describes the Brussels killings as an “attack against the Jews,” said Belgian federal prosecutor Frederic Van Leeuw.

Molins said at a news conference that the video was found on a camera among Nemmouche’s belongings during his arrest Friday in Marseille. Nemmouche, 29, does not appear on the video but a voice believed to be his says he had recorded the video because he had not succeeded in recording the Brussels attack with a smaller, portable camera, Molins said.